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2004

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Articles 1591 - 1620 of 2785

Full-Text Articles in Engineering

Modeling And Simulation Of The Military Intelligence Process, Carl R. Pawling Mar 2004

Modeling And Simulation Of The Military Intelligence Process, Carl R. Pawling

Theses and Dissertations

There is concern within U.S. space and intelligence organizations that the current Tasking, Processing, Exploitation, and Dissemination processes may be insufficient to support current and future Intelligence, Surveillance, and Reconnaissance systems. As part of a larger intelligence process, more detailed analysis becomes critical to determine what portions need to be improved. This analysis can be accomplished by simulation, which is appropriate due to the complexity of the process and the ability to compare variations in the process. We construct a high level model of a generalized military intelligence process based in part on the Intelligence Cycle outlined in Joint Publications. …

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Atmospheric Simulation Using A Liquid Crystal Wavefront Controlling Device, Matthew R. Brooks Mar 2004

Atmospheric Simulation Using A Liquid Crystal Wavefront Controlling Device, Matthew R. Brooks

Theses and Dissertations

Test and evaluation of laser warning devices is important due to the increased use of laser devices in aerial applications. In this thesis, an atmospheric aberrating system is developed to enable in-lab testing of laser warning devices. This system employs laser light at 632.8nm from a Helium-Neon source and a spatial light modulator (SLM) to cause phase changes using a birefringent liquid crystal material. Before the system can be used, the SLM phase response must be quantified to ensure proper manipulation of index of refraction. Additionally, diffraction from the SLM and real-world system scaling are addressed. Once completed, the atmospheric …

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Target Recognition Using Linear Classification Of High Range Resolution Radar Profiles, Ricardo A. Diaz Mar 2004

Target Recognition Using Linear Classification Of High Range Resolution Radar Profiles, Ricardo A. Diaz

Theses and Dissertations

High Range Resolution (HRR) radar profiles map three-dimensional target characteristics onto one-dimensional signals that represent reflected radar intensity along target extent. In this thesis, second through fourth statistical moments are extracted from HRR profiles and input to Fisher Linear Discriminant (FLD) classifiers. An iterative classification process is applied that gradually minimizes required a priori knowledge about the target data. It is found that the second through fourth statistical moments of HRR profiles are useful features in the FLD classification of dissimilar targets and they provide reasonable discrimination of similar targets. Greater than 69% correct classification for two-target scenarios and greater …

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Reconstruction Algorithm Characterization And Performance Monitoring In Limited-Angle Chromotography, Kevin C. Gustke Mar 2004

Reconstruction Algorithm Characterization And Performance Monitoring In Limited-Angle Chromotography, Kevin C. Gustke

Theses and Dissertations

Hyperspectral data collection and analysis is an increasing priority with the growing need to obtain greater classification precision than offered by traditional spatial imagery. In this thesis, trends in hyperspectral chromotomographic reconstruction are explored where reconstruction is performed using a series of spatial-chromatic images. Chromotomography involves capturing a series of two-dimensional images where each image is created by placing a prism in front of the focal plane array; causing spectral dispersion corresponding to a series of prism angles over a single rotation. Before testing reconstruction, synthetic data is produced, approximating what would be produced from prism dispersion on the focal …

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Microprocessor-Based Systems Control For The Rigidized Inflatable Get-Away-Special Experiment, David C. Moody Mar 2004

Microprocessor-Based Systems Control For The Rigidized Inflatable Get-Away-Special Experiment, David C. Moody

Theses and Dissertations

As the demand for space based communications and faster data throughput increase, satellites are becoming larger. Larger satellite antennas help to provide the needed gain to increase communications in space. Compounding the performance and size trade-offs are the payload weight and size limit imposed by the launch vehicles. Inflatable structures offer a cost saving opportunity since the structure is significantly lighter and has a reduced storage volume. This allows for smaller launch vehicles and for increased performance capabilities. Inflatable structures offer possibilities for increased satellite lifetimes, increased communications capacity, and reduce launch costs. This thesis develops and implements the computer …

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Magnetogasdynamic Flow Control Of A Mach Reflection, Brian E. Earp Mar 2004

Magnetogasdynamic Flow Control Of A Mach Reflection, Brian E. Earp

Theses and Dissertations

Two-dimensional regular and Mach reflections have been studied in the Mach 4.96 dual-solution domain for a 25° and 26° double-fin inlet. The steady-state computational Mach and regular reflections were subjected to magnetogasdynamic forces to determine whether these forces could be used as a possible flow control mechanism. The numerical code employed for this research solved the inviscid Euler equations with added source terms for the ponderomotive force and accompanying energy interactions. The 25° regular reflection was determined to be extremely sensitive to a decelerating Lorentz force. Transient application of the force led to the transition of the regular reflection to …

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Characterization Of The Target-Mount Interaction In Radar Cross Section Measurement Calibrations, Donald W. Powers Mar 2004

Characterization Of The Target-Mount Interaction In Radar Cross Section Measurement Calibrations, Donald W. Powers

Theses and Dissertations

Radar Cross Section (RCS) measurements are quintessential in understanding target scattering phenomenon. The reduced RCS of modern weapons systems stresses the capability of current RCS measurement ranges. A limiting factor that has recently become more significant is the electromagnetic coupling between a test target and the mounting hardware used to support it and control its orientation during the RCS measurement. Equally important is the electromagnetic coupling between the RCS calibration artifact and its mount, which provides an opportunity to explore the coupling phenomena without delving into operationally sensitive areas. The primary research goal was to characterize the interaction between a …

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Demonstrating Optothermal Actuators For An Autonomous Mems Microrobot, Francis R. Szabo Mar 2004

Demonstrating Optothermal Actuators For An Autonomous Mems Microrobot, Francis R. Szabo

Theses and Dissertations

There are numerous applications for microrobots which are beneficial to the Air Force. However, the microrobotics field is still in its infancy, and will require extensive basic research before these applications can be fielded. The biggest hurdle to be solved, in order to create autonomous microrobots, is generating power for their actuator engines. Most present actuators require orders of magnitude more power than is presently available from micropower sources. To enable smaller microrobots, this research proposed a simplified power concept that eliminates the need for on-board power supplies and control circuitry by using actuators powered wirelessly from the environment. This …

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Using Value-Focused Thinking To Evaluate The Effectiveness Of Air Force Utility Privatization, Carlos Braziel Mar 2004

Using Value-Focused Thinking To Evaluate The Effectiveness Of Air Force Utility Privatization, Carlos Braziel

Theses and Dissertations

The majority of the Air Force s stateside utility systems are old, obsolete, and unreliable. The cost to upgrade and repair these systems is currently estimated at over $4 billion. In response, the Air Force began efforts to convey ownership of these utility systems to the private sector through privatization efforts. However, privatization critics believe that newly privatized entities of government will cost the public more money and provide a lower level of service. Therefore, independent audits are a necessity to ensure government initiatives, meet their intended goals. However, the Air Force currently lacks an effective auditing tool to ensure …

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Characterization Of Microbial Processes That Degrade Chlorinated Solvents In A Constructed Wetland Using Organic Acid And Inorganic Anion Concentration Profiles, Chad B. Bondurant Mar 2004

Characterization Of Microbial Processes That Degrade Chlorinated Solvents In A Constructed Wetland Using Organic Acid And Inorganic Anion Concentration Profiles, Chad B. Bondurant

Theses and Dissertations

Chlorinated solvents have been used in industrial cleaning and degreasing processes in the United States since the early 1900s, and their induction into the environment increased significantly with the growth of industrial processes over the past century. PCE, TCE and their daughter products have been associated with a number of human health concerns and are currently the most common contaminants found in groundwater in the United States. Wetlands possess characteristics necessary for the complete degradation of chlorinated ethenes by microorganisms via anaerobic and aerobic regions that foster the necessary oxidation-reduction conditions. Organic acid and inorganic anion concentrations were evaluated in …

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Developing Team Cohesion: A Quasi-Field Experiment, John F. Costello Mar 2004

Developing Team Cohesion: A Quasi-Field Experiment, John F. Costello

Theses and Dissertations

Within military organizations, research findings have lent support to the positive influence cohesion has on group performance in combat and non-combat areas, Beyond performance, research findings show that cohesion influences the job satisfaction, and health of military members, particularly under highly stressful conditions, such as those encountered in combat or extended deployments. The purpose of this research effort is to further analyze the strategies that should be used to develop cohesiveness among Air Force members. This was done by testing the extent to which cohesion changed when familiarization and challenging situations were coupled in a technical training course geared towards …

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Recovering From A Stalled Change Initiative: A Case Of Correcting Implementation Mistakes, Ellen L. Dorey Mar 2004

Recovering From A Stalled Change Initiative: A Case Of Correcting Implementation Mistakes, Ellen L. Dorey

Theses and Dissertations

Amid an age of increasing technology, innovation, and global business competition, there is no question that the pace organizational changes are introduced will increase, as well. With this pace of change, organizational leaders might find themselves short on the time and resources necessary to properly create readiness by utilizing implementation strategies. Frequently, a change initiative that is not introduced properly will meet resistance within the organization. When strong resistance is encountered, the initiative is often abandoned and replaced with some other effort. However, in some situations, the initiative can not be abandoned and implementation must continue. This research effort sought …

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A Study Of Information Exchange Between United States Air Force Bases And Their Surrounding Communities, Andrew C. Clewett Mar 2004

A Study Of Information Exchange Between United States Air Force Bases And Their Surrounding Communities, Andrew C. Clewett

Theses and Dissertations

Data, information, and knowledge are exchanged daily from United States Air Force (USAF) bases to surrounding communities. The purpose of this research is to aid managers and commanders in gaining a better understanding of their information flow and bettering their information management practices. The research specifically seeks answers to the questions of where information is exchanged, why information is exchanged, and to whom information is exchanged with.

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The Application Of Value Focused Thinking To Utilities Privatization Source Selection, J. Heath Duncan Mar 2004

The Application Of Value Focused Thinking To Utilities Privatization Source Selection, J. Heath Duncan

Theses and Dissertations

The Department of Defense's utility systems have suffered from under-funding and lack of technology investment, thereby creating a service gap between these DoD systems and systems operated by commercial providers. In order to overcome this gap and refurbish their systems, the DoD has focused its efforts on privatization of these systems. The utilities privatization decision is extremely vital and permanent and thus warrants backup source selection methodologies. Since awarding contracts in the utilities privatization arena requires a decision considering tradeoffs between multiple competing objectives, a value-focused thinking approach was used to create a structured, standardized value model taking into account …

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Policy Analysis Of Chapter 101a, Readiness And Range Preservation, Of The National Defense Authorization Act For Fiscal Year 2004, William E. Sitzabee Mar 2004

Policy Analysis Of Chapter 101a, Readiness And Range Preservation, Of The National Defense Authorization Act For Fiscal Year 2004, William E. Sitzabee

Theses and Dissertations

This research analyzed the United States Air Force's ability to meet the two conditions required for exemptions of critical habitat designations that are authorized under the National Defense Authorization Act for Fiscal Year 2004. The research was limited to natural resources management on United States Air Force training ranges. Department of Defense exemptions can only be achieved if two conditions exist: the management activities must meet the intent of the Endangered Species Act and conserve the threatened and endangered species identified on the lands managed under an Integrated Natural Resources Management Plan (INRMP), and the plan must ensure that there …

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Application Of Horizontal Flow Treatment Wells For In Situ Treatment Of Mtbe-Contaminated Groundwater, Preston F. Rufe Mar 2004

Application Of Horizontal Flow Treatment Wells For In Situ Treatment Of Mtbe-Contaminated Groundwater, Preston F. Rufe

Theses and Dissertations

This study utilized a three-dimensional numerical model to evaluate the potential application of HFTWs to manage MTBE-contaminated groundwater. HFTWs consist of two dual-screened treatment wells. One well operates in an upflow mode, with MTBE-contaminated water extracted from an aquifer through a screen in the deep portion of an aquifer and injected into the aquifer through a shallow well screen, while the adjacent well operates in a downflow mode, extracting water from the shallow zone of the aquifer and injecting it into the deep zone. As the MTBE-contaminated water flows through the wells, an electron acceptor and/or another electron donor is …

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Performance Study Of Two-Stage-To-Orbit Reusable Launch Vehicle Propulsion Alternatives, Marc A. Brock Mar 2004

Performance Study Of Two-Stage-To-Orbit Reusable Launch Vehicle Propulsion Alternatives, Marc A. Brock

Theses and Dissertations

This study investigated the performance of five Two-Stage-To-Orbit reusable launch vehicles (RLV), with stages propelled by rocket engines, turbojet engines and Rocket Based Combined Cycle (RBCC) engines. Horizontal versus vertical takeoff launch and direct versus lifting ascent trajectories were also studied. A method was conceived using a 3 degree of freedom optimization program, stage inert mass fractions, and a fixed gross takeoff weight (GTOW) of 1,000,000 lbf to determine each RLVs performance based on payload weight delivered to orbit and total vehicle inert weight. RLV trajectory constraints, mass fractions, engine performance, and aerodynamics were assumed from literature of similar RLVs …

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Infrared Methods For Daylight Acquisition Of Leo Satellites, Joel E. Nelson Mar 2004

Infrared Methods For Daylight Acquisition Of Leo Satellites, Joel E. Nelson

Theses and Dissertations

Raven is an award-winning optical system design paradigm that couples commercially available hardware and software along with custom data analysis and control software to produce low-cost, autonomous, and very capable space surveillance systems. The first product of the Raven program was a family of telescopes capable of generating world-class optical observation data of deep-space satellites. The key to this system was the use of astrometric techniques for position and brightness data. Astrometry compares a satellite to the star background within the sensor field of view; since the position and brightness of the star-field is well known in star catalogs, accurate …

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Characterization And Ground Test Of An Inflatable Rigidizable Space Experiment, Steven N. Lindemuth Mar 2004

Characterization And Ground Test Of An Inflatable Rigidizable Space Experiment, Steven N. Lindemuth

Theses and Dissertations

As greater capability is demanded of space-based assets, their size and complexity are growing. Inflatable, rigidizable structures offer significant improvements in the areas of weight, size, and complexity over traditional mechanically deployed systems. These structures are not well understood and little testing of them has been done in the space environment. Widespread acceptance of these technologies will not be achieved without significant reduction in the risk of using inflatable, rigidizable structures in space. The goal of this experiment is to verify and validate ground testing of small tubular truss structures for use in space. This experiment builds on previous research …

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Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 20, Number 5, March 2004, College Of Engineering And Computer Science, Wright State University Mar 2004

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 20, Number 5, March 2004, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A ten page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

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Inside Unlv, Katrina Hudak, Carol C. Harter, James Frey Mar 2004

Inside Unlv, Katrina Hudak, Carol C. Harter, James Frey

Inside UNLV

No abstract provided.

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Evaluation Of Traffic Information And Prediction System (Tips) As Work Zone Traffic Control, Jerry G. Pigman, Kenneth R. Agent Mar 2004

Evaluation Of Traffic Information And Prediction System (Tips) As Work Zone Traffic Control, Jerry G. Pigman, Kenneth R. Agent

Kentucky Transportation Center Research Report

As part of a pavement rehabilitation project on I-64, the Traffic Information and Prediction System (TIPS) was installed as a means of providing real-time data for motorists in advance and through the work zone. This system collects real-time data using roadside non-contact (microwave) sensors, processes the data in a personal computer, calculates travel time between different points on the roadway, and displays the travel time information on several portable changeable message signs positioned at pre-determined locations along the roadway. The system displays information in the form of travel time and distance through the work zone. The objective of this report …

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Astronaut Eva Exposure Estimates From Cad Model Spacesuit Geometry, Giovanni De Angelis, Brooke M. Anderson, William Atwell, John E. Nealy, Gary D. Qualls, John W. Wilson Mar 2004

Astronaut Eva Exposure Estimates From Cad Model Spacesuit Geometry, Giovanni De Angelis, Brooke M. Anderson, William Atwell, John E. Nealy, Gary D. Qualls, John W. Wilson

Mathematics & Statistics Faculty Publications

Ongoing assembly and maintenance activities at the International Space Station (ISS) require much more extravehicular activity (EVA) than did the earlier U.S. Space Shuttle missions. It is thus desirable to determine and analyze, and possibly foresee, as accurately as possible what radiation exposures crew members involved in EVAs will experience in order to minimize risks and to establish exposure limits that must not to be exceeded. A detailed CAD model of the U.S. Space Shuttle EVA Spacesuit, developed at NASA Langley Research Center (LaRC), is used to represent the directional shielding of an astronaut; it has detailed helmet and backpack …

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Continue Stress Corrosion Cracking/ Electrochemical Testing And Model Support, L. G. Mcmillion, K. S. Raja, S. Namjoshi, Amy J. Smiecinski Mar 2004

Continue Stress Corrosion Cracking/ Electrochemical Testing And Model Support, L. G. Mcmillion, K. S. Raja, S. Namjoshi, Amy J. Smiecinski

Publications (YM)

The work reported here is focused on measuring values for various model parameters for the General Corrosion Model (GCM). The objective of the UNR work is to obtain the parameter values under Quality Assurance protocols, so that the data can be incorporated into models that might be used to address licensing issues, for example. The derived kinetic parameters may be used in models for predicting the accumulation of general and localized corrosion damage to Alloy-22 canisters over the 10,000-year lifetime of the YM repository. The work focuses on obtaining data of the highest possible accuracy to derive kinetic parameters for …

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Estimative Current Mode Control Technique For Dc-Dc Converters Operating In Discontinuous Conduction Mode, Mehdi Ferdowsi, Ali Emadi Mar 2004

Estimative Current Mode Control Technique For Dc-Dc Converters Operating In Discontinuous Conduction Mode, Mehdi Ferdowsi, Ali Emadi

Electrical and Computer Engineering Faculty Research & Creative Works

A new control technique for DC-DC converters is introduced and applied to a boost converter operating in discontinuous conduction mode (DCM). In contrast to conventional control methods, the principal idea of the proposed control scheme is to obtain samples of the required signals and estimate the required switch-on time. The proposed technique is applicable to any converter operating in DCM, including power factor correctors (PFC), however, this letter mainly focuses on boost topology. In this letter, the main mathematical concept of a new control algorithm is introduced, as well as the robustness investigation of the proposed method with simulation and …

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A False Acceptance Error Controlling Method For Hyperspherical Classifiers, Chen-Wen Yen, Chieh-Neng Young, Mark L. Nagurka Mar 2004

A False Acceptance Error Controlling Method For Hyperspherical Classifiers, Chen-Wen Yen, Chieh-Neng Young, Mark L. Nagurka

Mechanical Engineering Faculty Research and Publications

Controlling false acceptance errors is of critical importance in many pattern recognition applications, including signature and speaker verification problems. Toward this goal, this paper presents two post-processing methods to improve the performance of hyperspherical classifiers in rejecting patterns from unknown classes. The first method uses a self-organizational approach to design minimum radius hyperspheres, reducing the redundancy of the class region defined by the hyperspherical classifiers. The second method removes additional redundant class regions from the hyperspheres by using a clustering technique to generate a number of smaller hyperspheres. Simulation and experimental results demonstrate that by removing redundant regions these two …

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Bs News Mar 2004

Bs News

Building Services Engineering

No abstract provided.

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Investigation Of Novel Liquid Crystal Materials For Their Possible Applications, Minseok Chang Mar 2004

Investigation Of Novel Liquid Crystal Materials For Their Possible Applications, Minseok Chang

Masters

In this thesis I present four main topics. One is an introduction to liquid crystals and the second is an opto-electronic experimental setup. The third is an investigation of the dynamic properties of dendrimers, which show ferroelectric features. The last one is a research focused on understanding of the structures of two different types of De Vries smectic A liquid crystal phases. All research activities are performed by the hand-made but automatically controlled opto-electronic experimental setup. First, an introduction to liquid crystals is presented in easy language. Mainly there are two kinds of liquid crystals, thermotropic and lyotropic, but I …

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Annealing-Induced Full Amorphization In A Multicomponent Metallic Film, J. P. Chu, C. T. Liu, T. Mahalingam, S. F. Wang, Matthew O'Keefe, Benedict Y. Johnson, C. H. Kuo Mar 2004

Annealing-Induced Full Amorphization In A Multicomponent Metallic Film, J. P. Chu, C. T. Liu, T. Mahalingam, S. F. Wang, Matthew O'Keefe, Benedict Y. Johnson, C. H. Kuo

Materials Science and Engineering Faculty Research & Creative Works

We present direct experimental evidence that controllable amorphization and nanocrystallization during annealing of metastable films could serve as a precursor for exciting nanomaterials. The interesting discovery is that certain sputtered crystalline films become completely amorphous when annealed in the temperature range between the glass temperature and the crystallization temperature. Unlike other metallic glassy materials that exhibit annealing-induced devitrification, our good glass-forming films are transformed into various nanoscale and amorphous structures due to the annealing process. The formation of an amorphous phase gives rise to notable alterations in the electrical and mechanical properties of the film.

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A Switched Reluctance Machine-Based Starter/Alternator For More Electric Cars, Babak Fahimi, Ali Emadi, Raymond B. Sepe Mar 2004

A Switched Reluctance Machine-Based Starter/Alternator For More Electric Cars, Babak Fahimi, Ali Emadi, Raymond B. Sepe

Electrical and Computer Engineering Faculty Research & Creative Works

Switched reluctance machines (SRMs) are considered as serious candidates for starter/alternator (S/A) systems in more electric cars. Robust performance in the presence of high temperature, safe operation, offering high efficiency, and a very long constant power region, along with a rugged structure contribute to their suitability for this high impact application. to enhance these qualities, we have developed key technologies including sensor less operation over the entire speed range and closed-loop torque and speed regulation. the present paper offers an in-depth analysis of the drive dynamics during motoring and generating modes of operation. These findings will be used to explain …

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